POS0342 ANTI-TUMOUR NECROSIS FACTOR (aTNF) WEANING STRATEGY IN JUVENILE IDIOPATHIC ARTHRITIS (JIA): DOES LONGER DURATION MATTER?
Authors: T. Arkachaisri, K. L. Teh, Y. X. Book, X. Gao, L. Das
Journal: Annals of the Rheumatic Diseases (2022)

Background The efficacy of aTNF in the treatment of children with JIA has been demonstrated. However, once the disease is under control, strategy towards discontinuing aTNF should be considered. Thus far, there is no convincing information regarding how biologics should be weaned. Objectives To compare the outcomes of a short- and long-weaning strategies of aTNF in our prospective observational JIA cohort Methods Children with JIA taking aTNF with at least 6 months follow-up duration were recruited from our JIA registry (May 2010-Jan 2022) at KK Women’s and Children’s Hospital, Singapore. Once remission on medication, ROM 1 (including no enthesitis and sacroiliitis by MRI for ERA) was achieved, aTNF was weaned according to 2 different protocols– short (Etanercept every 2 weeks, and Adalimumab every 4 weeks, for 6 months) and long (extending frequency by every 2 weeks for 3 cycles until reaching 12 weekly interval for another 3 cycles then stop biologic thereafter) protocols. Flare (recurrent of arthritis, enthesitis or uveitis) rates were compared, and potential predictors were assessed. Nonparametric statistics were used to described data and logistic regression and Kaplan-Meier analyses were used to assess clinical parameters and outcome association and cumulative probability of disease flare, respectively. Results Out of 143 JIA patients, 105 (78% male, 82% Chinese; enthesitis related arthritis 78%, oligoarticular JIA 9%, polyarticular JIA 11%, psoriatic arthritis 1%, undifferentiated JIA 1%) underwent aTNF weaning with 53% on short- and 47% on long-weaning protocol. Median disease duration at aTNF start was 13.5 (10.6-15.8) and duration of follow-up was 6.6 (3.9-9.5) years. There was no significant difference in demographic and clinical parameters between groups. There was none of the short- but 49% of the long-weaning group flared during the weaning period, Table 1. However, no significant difference in the total flare rate (during and after stopping aTNF) was observed between the 2 groups despite less patient flare after stopping aTNF in the later, p=0.004. Median time to flare after stopping aTNF was not different, p=0.270. Furthermore, probability of flare after stopping aTNF was not different as well, Log Rank p=0.095, Figure 1. Positive ANA predicts flare during weaning (OR 5.2, 95%CI: 1.224-22.416, p=0.026), but none of clinical parameters were associated with risk of flare after discontinuing aTNF therapy in our cohort. Table 1. Rate of flare and duration related to aTNF between short- and long-weaning groups FLARE Total (n=105) Short (n=56) Long (n=49) p Number of JIA patients flared during wean (% ) 24 (22.9) 0 (0.0) 24 (49.0) &lt;0.001 Time to flare during aTNF weaning after starting (month)* 6.5 (4.5-14.5) Number of JIA patients flared after DC aTNF (% ) 50 (47.6) 34 (60.7) 16† (32.7) 0.004 Time to flare after stopping aTNF (month)* 6.2 (2.7-11.8) 6.9 (5.5-11.6) 0.270 Total number of patients who flared 68 (64.8) 34 (60.7) 34 (69.4) 0.353 *Median (interquartile range), †included 6 patients who flare during weaning and after stopping aTNF, aTNF = anti-tumour necrosis factor Figure 1. Cumulative probability of flare between the short- and long-weaning group after discontinuing aTNF therapy Conclusion Duration of spacing out the aTNF therapy after achieving ROM may not minimize the flare rate or delay time to flare after stopping the therapy in JIA patients. Further validation in larger multinational longitudinal cohorts is required to confirm our initial findings. References [1]Wallace CA, Giannini EH, Huang B, et al. American College of Rheumatology provisional criteria for defining clinical inactive disease in select categories of juvenile idiopathic arthritis. Arthritis care &amp; research 2011;63(7):929-36. Disclosure of Interests None declared